the animal kingdom as you've never seen it before. looking just like us. >>> from new york city, this is "nightline." >> good evening and thank you for joining us. tonight we begin with the twisted tale of love gone deadly wrong of today jodi arias, the young woman on trial for murder in phoenix, arizona, took the stand for a second day to try to convince a jury that when she stabbed, slashed and shot her one-time boyfriend, it was all in self-defense. but that wasn't always her story. she faces the possibility of the death penalty. abc has this report for the series, crime and punishment. >> did you kill travis alexander on june 4th, 2008? >> yes, i did. >> it is the level equivalent of a hail mary pass. the defense attorneys almost never want to put a client on the stand. when that client is an admitted killer and a serial liar, there isn't much choice. >> how are you feeling right now? >> nervous. >> jodi arias could face the death penalty if she is convicted of murdering her ex-boyfriend, travis alexander. the 30-year-old mormon b